CA1200741A - Method and apparatus for sectionwise heat treatment of component parts of ferrous materials - Google Patents
Method and apparatus for sectionwise heat treatment of component parts of ferrous materialsInfo
- Publication number
- CA1200741A CA1200741A CA000403373A CA403373A CA1200741A CA 1200741 A CA1200741 A CA 1200741A CA 000403373 A CA000403373 A CA 000403373A CA 403373 A CA403373 A CA 403373A CA 1200741 A CA1200741 A CA 1200741A
- Authority
- CA
- Canada
- Prior art keywords
- bath
- heat treatment
- quenching
- treated
- component parts
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D5/00—Heat treatments of cast-iron
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
- C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
- C21D1/20—Isothermal quenching, e.g. bainitic hardening
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/62—Quenching devices
- C21D1/63—Quenching devices for bath quenching
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- Processing Of Solid Wastes (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Furnace Charging Or Discharging (AREA)
Abstract
A b s t r a c t By means of partial hardening of component part at the bainite stage, combinations of high-tensile skin layer properties with the basic properties of the cast material are made possible. The part processed this way has a low heat distortion and is easy to machine when hardened.
Component sections are being heated up to austenitizing temperatures and subsequently quenched in a hot bath, in which the material is being transformed according to the time-temperature-transformation of the material.
(Fig. 2)
Component sections are being heated up to austenitizing temperatures and subsequently quenched in a hot bath, in which the material is being transformed according to the time-temperature-transformation of the material.
(Fig. 2)
Description
The present application refers to a method and an apparatus Eor partial heat treatrnent of component parts of ferrous metals.
In order to obtain hig-tensile structural properties it is known to submit component parts, as axles, toothed rims, spur wheels, shift forks, to an isothermal heat treatment at the bainitic stage. Thereby, the component parts are being completel~ austenitized and consequently transformed in a maintaining bath.
Ihe existing known method has the following disadvantages:
The high-tensile structural properties of bainite are being transferred to sections of the component parts, in which sections no such properties are not desired.
- The special treatment processes required after hardening and the measurement changes over the entire component parts.
Ihe object of the present invention is to develop an econo-mical method and an apparatus enabling a partial formation of bainite on the component.
Further objects are the elimination of problems in connec-tiOII with the distortion, sequential processing of spots not hardened and to achieve extended property combinations.
A method in accordance with the present invention, partial heat treatment of components of ferrous metals includes the steps that the sections to be treated are austenitized and subsequentl~ left in a quenching medium till the desired transformation has taken place so that a partial bainite structure results~
~.
.~ ~....
~Ifd`;~ f~
An apparatus in accordance with the present invention for the partial heat treatment of components of ferrous metals wherein the components to be treated are austenitized and then quenched, wherein a quenching bath is placed below the heating station into which bath the component falls immediately after heating.
In the following the invention is being described with reference to ~he drawings, in which Fig. 1 shows a schematic view of a plant for isother-mal processing of ferrous parts in the bainite stage, and Fig. 2 shows the temperature curves of a random com ponent part as well as the expected form of the structure~
Test bodies with dimensions of 16 x 20 mm with predominantly pearlitic structures were provided with bainitic outer zones.
Test bodies of a raw material of the composition:
3,65 weight percent C, 2~38 weight percent Si, 0,46 weight percent Mn, remnant Fe and with a structure of 75 percent pearlite and 25 percent ferrite were partially heat treated.
At first the sections to be treated were inductively he~ted to a temperature between 850 and 1000 centigrades.
The height of fall between the heating coil and the harde-ning bath was set at approx. 90 mm. Subsequen~ly, the test body was held in the salt bath at 275 centigrades for 120 minutes r The test of the method was carr7ed out on a gear wheel modulus 3, The raw material was GGG (spheroidal graphite cast iron) with a pearlitic basic structure.
The heating was carried out, as with the test samples, up to a temperature of 900 centigradQs. The heating time was 13 ~
32 seconds. Subsequently, the test wheel was held in a salt bath at 280 centigrades for 120 minutesO
Furthermore, gear wheels, module 3, were so processed, that a bainitic structure was created down to approx. 4 mm below the dedendum.
In the modified inductive heating plant shown in Fig/ 1 the quenching bath 1 is placed immediately below the induc-tive coil 2, so that the component 3 drops directly into the bath, without the usual arrangement whereby the compo-nent 3 is being sprayed by means of a sprinkler located between the induction coil and the bath l. The quenching medium can be a tempered salt bath or oil. It is, however, also possible to use a metal bath.
In Fig. 2 a component A is shown, while the expected struc-ture form together with the temperature to be expected are shown in the corresponding TTT-curvesO
It is shown that the bainitic structure has excellent wear properties at high tensile strengthsO
By usiny the described method excellent results were achieved~ At a bainite content of approx. 90 percent, hard-ness values in the range of 46 to 48 HRC were measured on the test body or sample~ On sample gear wheels the hardness values from the highest to the lowert point of the cog measured were in the range from 39 to 41 HRC.
In order to obtain hig-tensile structural properties it is known to submit component parts, as axles, toothed rims, spur wheels, shift forks, to an isothermal heat treatment at the bainitic stage. Thereby, the component parts are being completel~ austenitized and consequently transformed in a maintaining bath.
Ihe existing known method has the following disadvantages:
The high-tensile structural properties of bainite are being transferred to sections of the component parts, in which sections no such properties are not desired.
- The special treatment processes required after hardening and the measurement changes over the entire component parts.
Ihe object of the present invention is to develop an econo-mical method and an apparatus enabling a partial formation of bainite on the component.
Further objects are the elimination of problems in connec-tiOII with the distortion, sequential processing of spots not hardened and to achieve extended property combinations.
A method in accordance with the present invention, partial heat treatment of components of ferrous metals includes the steps that the sections to be treated are austenitized and subsequentl~ left in a quenching medium till the desired transformation has taken place so that a partial bainite structure results~
~.
.~ ~....
~Ifd`;~ f~
An apparatus in accordance with the present invention for the partial heat treatment of components of ferrous metals wherein the components to be treated are austenitized and then quenched, wherein a quenching bath is placed below the heating station into which bath the component falls immediately after heating.
In the following the invention is being described with reference to ~he drawings, in which Fig. 1 shows a schematic view of a plant for isother-mal processing of ferrous parts in the bainite stage, and Fig. 2 shows the temperature curves of a random com ponent part as well as the expected form of the structure~
Test bodies with dimensions of 16 x 20 mm with predominantly pearlitic structures were provided with bainitic outer zones.
Test bodies of a raw material of the composition:
3,65 weight percent C, 2~38 weight percent Si, 0,46 weight percent Mn, remnant Fe and with a structure of 75 percent pearlite and 25 percent ferrite were partially heat treated.
At first the sections to be treated were inductively he~ted to a temperature between 850 and 1000 centigrades.
The height of fall between the heating coil and the harde-ning bath was set at approx. 90 mm. Subsequen~ly, the test body was held in the salt bath at 275 centigrades for 120 minutes r The test of the method was carr7ed out on a gear wheel modulus 3, The raw material was GGG (spheroidal graphite cast iron) with a pearlitic basic structure.
The heating was carried out, as with the test samples, up to a temperature of 900 centigradQs. The heating time was 13 ~
32 seconds. Subsequently, the test wheel was held in a salt bath at 280 centigrades for 120 minutesO
Furthermore, gear wheels, module 3, were so processed, that a bainitic structure was created down to approx. 4 mm below the dedendum.
In the modified inductive heating plant shown in Fig/ 1 the quenching bath 1 is placed immediately below the induc-tive coil 2, so that the component 3 drops directly into the bath, without the usual arrangement whereby the compo-nent 3 is being sprayed by means of a sprinkler located between the induction coil and the bath l. The quenching medium can be a tempered salt bath or oil. It is, however, also possible to use a metal bath.
In Fig. 2 a component A is shown, while the expected struc-ture form together with the temperature to be expected are shown in the corresponding TTT-curvesO
It is shown that the bainitic structure has excellent wear properties at high tensile strengthsO
By usiny the described method excellent results were achieved~ At a bainite content of approx. 90 percent, hard-ness values in the range of 46 to 48 HRC were measured on the test body or sample~ On sample gear wheels the hardness values from the highest to the lowert point of the cog measured were in the range from 39 to 41 HRC.
Claims (7)
1. Method for partial heat treatment of com-ponents of ferrous metals, characterized in that the sections to be treated are being austenitized and subsequently left in a quenching medium until the desired transformation has taken place, so that a partial bainite structure results.
2. Method according to claim 1, characterized in that the sections to be treated are heated to a temperature of 850 to 1000 centigrades.
3. Method according to claim 1, characterized in that the quenching bath is a hot bath, the tempera-ture of which is being held at 180 to 450 centigrades.
4. Method according to claim 3, characterized in that as quenching medium a salt bath is being used.
5. Method according to claim 3, characterized in that as quenching medium oil is being used.
6. Method according to claim 3, characterized in that a metal bath is being used as quenching medium.
7. Apparatus for partial heat treatment of com-ponents of ferrous metals, wherein the components to be treated are austenitized and then quenched, and is characterized in that a quenching bath is placed below the heating place, into which bath the component falls immediately after heating.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH3312/81A CH653706A5 (en) | 1981-05-21 | 1981-05-21 | METHOD AND DEVICE FOR SECTIONAL HEAT TREATMENT OF COMPONENTS MADE OF FERROUS MATERIALS. |
| CH3312/81-2 | 1981-05-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1200741A true CA1200741A (en) | 1986-02-18 |
Family
ID=4253262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000403373A Expired CA1200741A (en) | 1981-05-21 | 1982-05-20 | Method and apparatus for sectionwise heat treatment of component parts of ferrous materials |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0065678B1 (en) |
| JP (1) | JPS57194208A (en) |
| AT (1) | ATE27465T1 (en) |
| BR (1) | BR8202893A (en) |
| CA (1) | CA1200741A (en) |
| CH (1) | CH653706A5 (en) |
| DE (1) | DE3276438D1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5028281A (en) * | 1988-06-14 | 1991-07-02 | Textron, Inc. | Camshaft |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3580938B2 (en) * | 1996-03-05 | 2004-10-27 | アイシン・エィ・ダブリュ株式会社 | Heated bainite treatment method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1687656A (en) * | 1925-07-23 | 1928-10-16 | Westinghouse Electric & Mfg Co | Heat-treating method |
| DE1113225B (en) * | 1957-09-19 | 1961-08-31 | Tiroler Roehren & Metallwerk | Process for surface hardening of cast iron |
| AT303097B (en) * | 1969-03-06 | 1972-11-10 | Boehler & Co Ag Geb | Partial hardening process |
| US3860457A (en) * | 1972-07-12 | 1975-01-14 | Kymin Oy Kymmene Ab | A ductile iron and method of making it |
-
1981
- 1981-05-21 CH CH3312/81A patent/CH653706A5/en not_active IP Right Cessation
-
1982
- 1982-05-06 AT AT82103913T patent/ATE27465T1/en not_active IP Right Cessation
- 1982-05-06 EP EP82103913A patent/EP0065678B1/en not_active Expired
- 1982-05-06 DE DE8282103913T patent/DE3276438D1/en not_active Expired
- 1982-05-13 JP JP57079267A patent/JPS57194208A/en active Pending
- 1982-05-19 BR BR8202893A patent/BR8202893A/en unknown
- 1982-05-20 CA CA000403373A patent/CA1200741A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5028281A (en) * | 1988-06-14 | 1991-07-02 | Textron, Inc. | Camshaft |
Also Published As
| Publication number | Publication date |
|---|---|
| ATE27465T1 (en) | 1987-06-15 |
| JPS57194208A (en) | 1982-11-29 |
| EP0065678B1 (en) | 1987-05-27 |
| DE3276438D1 (en) | 1987-07-02 |
| BR8202893A (en) | 1983-05-03 |
| EP0065678A1 (en) | 1982-12-01 |
| CH653706A5 (en) | 1986-01-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |